Richard Greenberg’s Our Mother’s Brief Affair, now playing at Manhattan Theatre Club, directed by Lynne Meadow, sounded like a deliciously, gossipy upscale romance, with or without dramatic consequences. How wrong that thinking was. This production is neither delicious nor gossipy, but the dramatic consequences are a matter of interpretation. Linda Lavin, the consummate comedienne on the Broadway stage, almost always in the role of sharp-tongued mother, gets even more material here. Her character, Anna, is mother to young adult twins, Seth (Greg Keller) and Abby (Kate Arrington). Anna, from Long Island, now middle-aged and alone in a rest home in 2003, is aging too slowly for her frequent announcements that she’s saying goodbye. She becomes ill, she recovers, she complains. As a mother, she has always treated her twins with a lack of emotional presence. This is a woman comfortable in her private thoughts and memories, especially those memories that she’s embellished into life-affirming plots. Anna has a longtime secret, or so she remembers, and, on sequential visits with her children, when she’s not reminding each how much she preferred the other or why she was disappointed in having twins, she reveals bits and pieces of an untold sliver of her past.

The Act II memory sequence develops after the beginning of Anna’s brief affair with a lover named Phil (John Procaccino), whom she met on a Central Park bench, while Seth took endless viola lessons at Juilliard. In one flashback, Anna’s happiness is shattered, when Phil reveals his true name, a change of identity that’s hidden a devious, dark crime. Anna hears this, while she was living in her own alternate identity, as a rapturous, middle-aged lover in a New York hotel room. She had found escape from her angry and depressed husband, whom she married to escape an angry and depressed mother of her own, only to discover that her clandestine lover was a depressed recluse, hiding from society. The play’s two acts are non-sequitors, and the script needs more development or a division into two new pieces, one of romantic yearnings, the other of family betrayal. The two-act dialogue (and that’s all there is, with almost no action) just does not flow. Abby and Seth are also depressed and fraught, with Seth anxious about his sexual identity and relationships, and Abby, a gay young woman with a partner and child, having her own domestic anxiety. Meanwhile, Anna remains or returns (we are not certain as observers) to a New York hospital room, with vague medical deterioration and imploding delirium.

Ms. Meadow has directed Ms. Lavin extremely well, in that Anna is magnetic, especially in the 1973 park bench flashbacks, in her nice Burberry trench and lovely long scarf. Ms. Meadow places the twins behind the bench, as they listen to their mother’s revelatory adventures. But, Abby and Seth are never actually known, as they speak little, except to reveal their own insecurities and resentments about relationships, including their lifelong sibling rivalry. Mr. Keller and Ms. Arrington will have future opportunities for stronger roles. Mr. Procaccino, who was favorably reviewed on these pages in Incident in Vichy this season, as well as in An Enemy of the People and Nikolai and the Others, in recent years, was given too small a role in Mr. Greenberg’s play. Santo Loquasto’s set, however, with a bench that shifts to a hospital bed, and a stage that shifts from bucolic to sterile, is expertly conceived, as are all his scenic designs, here enhanced by Peter Kaczorowski’s fine lighting. Tom Broecker’s costumes are mainly remembered for the trench and scarf, while Fitz Patton’s sound is clear and crisp. I look forward to new experiences at Manhattan Theatre Club, which always presents plays that activate mind and heart.